Water Cycle and Water Insecurity- EQ2
Drought= a shortfall or deficiency of water over an extended time period.
Famine drought= widespread failure of agricultural systems, food shortages develop into famines that
have severe social, economic and environmental impacts, caused by increased water demand or
natural variability in the climate.
Agricultural drought= can be accelerated by farming practices such as overgrazing. Rainfall deficiency
leads to a deficiency in soil moisture and soil water availability.
Meteorological drought= shortfalls in precipitation due to short-term variability, or longer-term trends,
which increase the duration of the dry period. Lack of rainfall is often combined with high
temperatures, high winds, strong sunshine and low humidity which increases evaporation.
Hydrological drought= reduced stream flow and groundwater levels which decrease because of reduced
inputs of precipitation and continued high rates of evaporation.
Impacts of different types of droughts-
Agricultural drought- economic loss agricultural income decrease, government aid, pasture and
livestock’s productivity decline, irrigation system fails, poor crop yields, decline in pasture
quality, reduced biomass.
Famine drought- increased starvation, healthcare demand is high and insufficient resources, food
shortages, international aid and rural-urban migration.
Meteorological drought- vegetation decline, loss of soil moisture, supply of irrigation water
declines.
Hydrological drought- aquatic ecosystem risks, poorer water quality, threats to wetlands and
habitats, less urban water supply, power generations restrictions, reduced water storage, water
use restrictions.
Measurements of drought-
- Palmer Drought Severity Index
- Crop Moisture Index
- Palmer Hydrological Drought Index
, El Nino Australia: key details-
Began in early 2020
Extreme high temperatures, rainfall below average in winter
Dam shortages dropped to 50%
Bored rivers between NSW and Queensland are at 6%
Total fire bans, aquatic habitats at risk, wetland areas dying, evacuation plans.
El Nino Papua New Guinea: key details-
Drought declared in 34 provinces in Indonesia
Tonga suffered drought for nearly a year
Increased precipitation, flooding and higher sea levels near the Equator
1/5th less water in country
Longer, more destructive cyclone season
Contaminated water supplies and severe frosts kill crops
4.1mil people at risk of food shortages and water insecurity
24% deaths from starvation.
2
